Coronary artery spasm after off-pump coronary artery bypass grafting

BACKGROUND: Coronary artery spasm (CAS) in the immediate postoperative period has been recognized as a possible cause for perioperative myocardial ischaemia after off-pump coronary artery bypass grafting (CABG). It varies in severity and can be associated with circulatory collapse and death. The purpose of this study was to present our experiences on CAS after off-pump CABG and detail its management. METHODS: The case reports of three patients with similar clinical presentations of ischaemic heart disease who underwent CABG using an off-pump technique are reviewed. Severe manifestations of CAS in the immediate postoperative period with documented angiographic findings are presented. RESULTS: Three patients (two men and one woman) with angina pectoris were diagnosed with coronary artery disease using coronary angiography. The elective off-pump CABG was uneventful; however, severe manifestation of myocardial ischaemia with abrupt onset developed at the intensive care unit. All three patients underwent immediate coronary angiography to verify the diagnosis of CAS. Apart from intracoronary nitroglycerine infusion and medical support with inotropic agents, extracorporeal membranous oxygenation was carried out because of severe haemodynamic deterioration in one case, while support was required with intraaortic balloon pumping in another. All three patients made a full recovery. CONCLUSION: Coronary artery spasm can severely complicate the postoperative course for patients undergoing off-pump CABG, leading to myocardial ischaemia or infarction, life-threatening arrhythmias, persistent hypotension and even cardiac arrest. Early awareness and diagnosis of CAS with the establishment of appropriate management strategies may prevent its potentially lethal consequences.     

A case of intimal dissection of the left internal mammary artery grafting

A 73-year-old man underwent reoperation using the in situ left internal mammary artery (IMA) because of the stenosis of the vein graft to the left anterior descending artery (LAD). The patient recovered free from angina but angiography performed 1 month after operation revealed the dissection of intima of the left IMA. Use of the IMA in coronary artery bypass grafting (CABG) is now generally accepted as the optimal method of myocardial revascuralization and the use of the left IMA to the LAD has become a routine procedure in our CABG surgery. However, because the IMA wall is friable and disruption occurs easily, especially in the elder, much care should be taken during mobilization of the IMA.     

Combined carotid endarterectomy and off-pump coronary artery bypass grafting

Patients with angina undergoing carotid endarterectomy have a high mortality. A 74-yaer-old man who has severe carotid stenosis was performed combined carotid endarterectomy and off-pump coronary artery bypass grafting successfully. At first, carotid endarterectomy was performed with Jamieson's specially designed dissector, which allow simultaneous dissection and removal blood from the surgical field. Secondly, then off-pump CABG was performed. Skeletonized internal mammary artery was harvested with ultrasound dissector. The advantage of that the dissected artery is not only long and greater blood flow, but also less damage to sternal blood flow which prevent infection and complications. Then internal mammary artery was anastomosed to left anterior discending artery with Octopus II stabilizer. After the operation, he recovered uneventfully without neurological complication. Combined single staged carotid endarterectomy and off-pump CABG appears to be a safe method.     

Off-pump coronary artery bypass grafting provides complete revascularization with reduced myocardial injury,transfusion requirements,and length of stay: a prospective randomized comparison of two hundred unselected patients undergoing off-pump versus conventional coronary artery bypass grafting

OBJECTIVE: Retrospective comparisons of selected patients undergoing off-pump versus conventional on-pump coronary artery bypass grafting have yielded inconsistent results and raised concerns about completeness of revascularization in off-pump coronary artery bypass grafting. METHODS: Two hundred unselected patients referred for elective primary coronary artery bypass grafting were randomly assigned to undergo off-pump coronary artery bypass grafting with an Octopus tissue stabilizer (Medtronic, Inc, Minneapolis, Minn) or conventional coronary artery bypass grafting with cardiopulmonary bypass by a single surgeon. Revascularization intent determined before random assignment was compared with the revascularization performed. All management followed strict, unbiased, criteria-driven protocols. Patients and nonoperative care providers were blinded to surgical group. RESULTS: Baseline characteristics were similar. The number of grafts performed per patient (mean +/- SD 3.39 +/- 1.04 for off-pump coronary artery bypass grafting, 3.40 +/- 1.08 for conventional coronary artery bypass grafting) and the index of completeness of revascularization (number of grafts performed/number of grafts intended, 1.00 +/- 0.18 for off-pump coronary artery bypass grafting, 1.01 +/- 0.09 for conventional coronary artery bypass grafting) were similar. Likewise, the index of completeness of revascularization was similar between groups for the lateral wall. Combined hospital and 30-day mortalities and stroke rates were similar. Postoperative myocardial serum enzyme measures were significantly lower after off-pump coronary artery bypass grafting, suggesting less myocardial injury. Adjusted postoperative thromboelastogram indices, fibrinogen, international normalized ratio, and platelet levels all showed significantly less coagulopathy after off-pump coronary artery bypass grafting. Patients undergoing off-pump coronary artery bypass grafting received fewer units of blood, were more likely to avoid transfusion altogether, and had a higher hematocrit at discharge. Cardiopulmonary bypass was an independent predictor of transfusion (odds ratio 2.42, P =.0073) by multivariate analysis. More patients undergoing off-pump coronary artery bypass grafting were extubated in the operating room and within 4 hours. Postoperative length of stay (in days) was shorter for off-pump coronary artery bypass grafting (5.1 +/- 6.5 for off-pump coronary artery bypass grafting, 6.1 +/- 8.2 for conventional coronary artery bypass grafting, P =.005 by Wilcoxon test). One patient (in the conventional coronary artery bypass grafting group) required angioplasty for graft closure within 30 days. CONCLUSIONS: When compared with conventional coronary artery bypass grafting with cardiopulmonary bypass, off-pump coronary artery bypass grafting achieved similar completeness of revascularization, similar in-hospital and 30-day outcomes, shorter length of stay, reduced transfusion requirement, and less myocardial injury.     

Off-pump coronary artery bypass grafting as re-do surgery in two cases in which the right gastroepiploic artery was grafted to the right coronary artery

Transdiaphragmatic off-pump coronary artery bypass grafting (OPCAB) to the right coronary artery, is an effective way to reduce the risks of second bypass surgery as well as the risk of graft injury after coronary artery bypass grafting (CABG). We report two cases of successful OPCAB as re-do surgery in which the right gastroepiploic artery (RGEA) was grafted to the right coronary artery. The first case was a 58-year-old woman, who underwent CABG 10 years ago. OPCAB (RGEA to right coronary artery) was performed since myocardial perfusion scintigraphy revealed ischemia in the inferior wall. The second case was a 67-year-old man who had hypertension, hyperlipidemia, peripheral arterial disease, and was undergoing dialysis (for 6 years). Six years previously, he developed a mycotic aneurysm of the right coronary artery and underwent open-heart surgery. He often had episodes of angina at night or during dialysis, and then developed congestive heart failure and was hospitalized. Since ischemia was considered to be in the inferior wall, the RGEA was grafted to the right coronary artery.     

From Vineberg to bypass: a "second-hand" internal mammary artery.

A patient operated upon 20 years ago for myocardial revascularization with two Vineberg procedures and one coronary artery bypass graft (CABG) on the right coronary artery had a recurrence of unstable angina due to the thrombosis of the left internal mammary artery (IMA) and the right CABG. The right IMA was patent but stenosed distally. Reoperation was performed with a direct end to side anastomosis of the patent right IMA onto the left anterior descending artery and a saphenous vein graft as a CABG on the marginal branch. We comment on the choice of this "second hand" IMA graft and the pathological appearances of the patent IMA.     

Anaesthesia for off-pump coronary artery bypass grafting surgery

Coronary artery bypass grafting (CABG) surgery may be undertaken with or without cardiopulmonary bypass (CPB) that is on- or off-pump. Although mortality and the incidences of coronary artery graft occlusion, myocardial infarction and stroke are equivalent, off-pump is associated with less blood loss, transfusion, requirement for inotropes, atrial fibrillation and chest infection compared with on-pump CABG surgery. Traditional high-dose opioid techniques of general anaesthesia should be avoided and either inhalation or total intravenous (IV) anaesthesia may be used. Meticulous monitoring, including electrocardiograph (ECG) and invasive arterial pressure measurement, is required. During grafting, good communication between anaesthetist and surgeon is essential. Maintenance of diastolic arterial pressure (DAP) is the key to preventing myocardial ischaemia and cardiovascular collapse. Surgical positioning for grafting to minimize hypotension is paramount and during grafting, IV fluid loading or vasoconstrictors and inotropes are effective treatments. Correction of bradycardia with atropine 0.3 mg IV or epicardial pacing also helps to maintain DAP. Persisting hypotension may require intra-aortic balloon pumping or conversion to on-pump CABG surgery. As there is less blood loss, there is a minimal requirement for cardiovascular support and early recovery of consciousness associated with off-pump compared with on-pump CABG surgery; patients in some institutions may be managed in a recovery room then transferred to a high-dependency unit, thus bypassing ICU.     

Left ventricular pseudo-false aneurysm after a myocardial infarction; application of heart positioner

We herein present the case of a pseudo-false aneurysm which developed in a patient after a myocardial infarction in the posterior left ventricular wall. A 71-year-old man experienced an acute myocardial infarction due to occlusion in the left circumflex artery. Five weeks after the myocardial infarction, echocardiography and magnetic resonance imaging (MRI) disclosed a pseudo-false aneurysm at the posterior left ventricular wall. A patch closure of the aneurysm and coronary artery bypass grafting (CABG) to both the left anterior descending artery and the left circumflex arteries were successfully performed. At surgery, the Starfish Heart Positioner, a commercially available device that is designed to lift the heart during off-pump CABG, was found to be very useful for exposing the posterior left ventricular wall by lifting and fixing the apex of the left ventricle.     

Ball thrombus induced by hibernating myocardium in the left ventricle; report of a case

An 80-year-old man was admitted to our hospital for examination of a ball thrombus incidentally found in the left ventricle (LV). Coronary angiogram revealed severe triple vessel disease and LV dysfunction. Although LV wall motion in the septum and the apex was akinetic, there were no signs of myocardial infarction. It was diagnosed as an acute LV ball thrombus with hibernating myocardium due to ischemia of the left anterior descending coronary artery. Emergency coronary artery bypass grafting (CABG) and excision of the thrombus were performed. Two weeks after surgery, LV function improved and the patient was discharged from the hospital without any complication. A LV ball thrombus without myocardial infarction is rare, and thought to be caused by hibernating myocardium.     

Off-pump coronary artery bypass grafting/beating coronary artery bypass grafting for a patient with low left ventricular ejection fraction

Beating coronary artery bypass grafting could be performed for a 47-year-old man with left ventricular ejection fraction (LVEF) of 9.3%. Post-operative LVEF was improved to 51.6%. Conventional coronary artery bypass grafting (CABG) used to be contraindicative for patients with LVEF below 20%. Recently, such patients are involved to indication of off-pump CABG (OPCAB) or beating CABG, because we consider OPCAB are lower complications than conventional CABG. We were able to bypass the circumflex for the patient while we had been used percutaneous cardio-pulmonary support (PCPS). We could perform beating coronary artery bypass grafting for a patient of the low LVEF.     

弥漫性冠状动脉病变的外科治疗

目的总结非体外循环心脏跳动下冠状动脉内膜剥脱后行非体外循环冠状动脉旁路移植术（off—pump CABG）治疗弥漫性冠状动脉病变的早期临床结果和经验，以提高手术疗效。方法2003年5月～2006年11月，对83例弥漫性冠状动脉病变患者在非体外循环下做冠状动脉内膜剥脱后行off—pump CABG，其中男61例，女22例；年龄55-80岁（65±7岁）；加拿大心脏病协会（CCS）心绞痛分级：Ⅱ级7例，Ⅲ级20例，Ⅳ级56例。有心肌梗死史36例（43．4％）。冠状动脉造影显示：双支血管病变5例，3支病变78例，其中合并左主干病变16例。左心室射血分数25％～65％（51％±16％）。83例共行110支冠状动脉内膜剥脱，其中左前降支系统67支，回旋支、钝缘支9支，右冠状动脉系统34支。20例内膜剥脱后先用大隐静脉片行左前降支成形，再在补片上用乳内动脉行旁路血管移植；应用左乳内动脉83支，桡动脉2支，余均为大隐静脉，每例移植血管3．9±1．2支。结果无手术死亡。术中移植血管血流满意101支（92％），血流量为22±16ml／min。术后发生心肌梗死4例，梗死面积小，无血流动力学改变，未给予特殊治疗。83例患者皆痊愈出院。随访75例（90．4％），8例失访，随访时间8～50个月，无心绞痛发作。8例患者在手术后3～29个月复查冠状动脉造影显示：冠状动脉内膜剥脱后行off—pump CABG的移植血管均通畅。结论非体外循环下冠状动脉内膜剥脱后行off—pump CABG，安全可行，再血管化程度高，是治疗弥漫性冠状动脉病变的有效方法。     

非体外循环冠状动脉旁路移植术围手术期心肌梗死发生率与移植血管血流量的关系

目的探讨冠状动脉旁路移植术（CABG）中移植血管血流量与围手术期心肌梗死（MI）发生率之间的关系,为临床提供借鉴。方法采集2010年1～6月在北京大学第一医院连续58例因冠心病接受单纯择期非体外循环冠状动脉旁路移植术（（）PcAB）患者的临床资料。术中均采用左乳内动脉（I,IMA）吻合于左前降支（I．AD）,其他靶血管则以大隐静脉（SV）作为旁路移植血管,在关胸前循环状态稳定条件下,应用瞬时流量测定技术测量各移植血管的血流量,并计算移植血管总血流量。根据术后是否发生围手术期MI,将患者分成两组：MI组11例,其中男7例,女4例;年龄67．4±10．3岁;非MI组,47例,其中男38例,女9例;年龄63．3±9．9岁。分析两组患者术前及术中的相关危险因素。结果MI组与非MI组的手术时间差异无统计学意义（205．44±59．6rainVS．183．4±32．4min,t=1．69l,P=0．096）。MI组与非MI组移植血管数量（3．00±1．oo支VS．2．96±0．78支,t=0．154,P=0．878）、LIMA-LAD移植血管血流量（15．40±）1．37mi／minVS．16．50±10．83mJ／min,f=0．301,P=0．764）差异均无统计学意义;MI组与非MI组移植血管总血流量（41．03土19．50ml／minVS．64．09±32．44ml／min,t=2．254,P=0．028）差异有统计学意义。移植血管总血流量〈48．5ml／min为发生MI的危险因素EoR：4．706,95％CI（1．099,20．147）]。结论移植血管总血流量可在一定程度上预测CABG后急性心肌缺血事件的发生,总血流量〈48．5ml／min的患者术后发生围手术期MI的概率将明显增加。     

Exposure and mechanical stabilization in off-pump coronary artery bypass grafting via sternotomy

Although off-pump coronary artery bypass grafting (CABG) is gaining popularity, obtaining exposure and stabilization of coronary arteries located on the lateral and inferior wall of the heart may be problematic. The aim of this study is to describe strategies and techniques of coronary exposure and mechanical stabilization that may be used to achieve total myocardial revascularization of the beating heart.     

Changes in jugular bulb oxygen saturation during off-pump coronary artery bypass graft surgery

BACKGROUND: The effect of haemodynamic derangement during coronary artery anastomosis in off-pump coronary artery bypass surgery on cerebral blood flow has not been elucidated. Jugular bulb oxygen saturation is a useful indicator of cerebral blood flow provided that the cerebral metabolic rate is constant. This study was designed to evaluate the changes in jugular bulb oxygen saturation during off-pump coronary artery bypass surgery. METHODS: With IRB approval, 48 patients were included. After anaesthesia, an 18-G catheter was introduced into the jugular bulb. Haemodynamic variables and oxygen profiles from gas analysis of jugular bulb blood and arterial blood were obtained: after sternotomy (baseline); at 5 min after the beginning of the anastomosis of the left anterior descending artery, obtuse marginal artery, and right coronary artery; and after sternal closure. RESULTS: Cardiac index and mixed venous oxygen saturation decreased significantly during anastomosis of all three arteries compared to the baseline value. Although the changes in jugular bulb oxygen saturation during anastomosis were statistically significant compared to its baseline value, jugular bulb oxygen saturation remained within normal limit throughout the study. CONCLUSIONS: Jugular bulb oxygen saturation, which represents the global cerebral oxygenation, was well maintained during the anastomosis of all coronary arteries despite significant haemodynamic changes during off-pump coronary artery bypass (OPCAB).     

Limits of arterial myocardial revascularization

A prospective study of myocardial blood perfusion after coronary artery bypass graft (CABG) was conducted in two groups of patients. In group 1, a two-year assessment by exercise thallium myocardial scintigraphy without medical treatment was performed in 122 patients who consecutively underwent CABG with exclusive use of both internal mammary arteries (IMA) and gastroepiploic artery (GEA). In group 2, myocardial function and perfusion were determined by radionuclide investigations performed before and one year after CABG in 100 patients with preoperative LV dysfunction (defined as LV ejection fraction (LVEF) less than 0.40), comparing results of myocardial revascularization performed with either exclusive arterial grafts (arterial group, 54 patients) or one arterial graft (IMA) associated with a sequential vein graft (vein group, 46 patients). In group 1, 21% of patients presented silent residual electric ischemia during exercise stress testing and 26% had reversible scintigraphic ischemic defect despite complete revascularization, 18% of those in the inferior wall bypassed with GEA and 8% in the anterior wall bypassed with the right IMA. In group 2, the significant preoperative ischemia significantly decreased in both the vein group and the arterial group. LV function was significantly improved in the vein group; in contrast there was no modification of LV function in the arterial group. A multivariate analysis showed that the surgical technique used and the preoperative LVEF were independent prognostic factors of the postoperative myocardial outcome, with a positive impact of the vein use on the postoperative myocardial function recovery. It is important to recognize that arterial grafts have some limitations in the ability to supply blood flow for coronary circulation that may induce postoperatively silent residual myocardial ischemia and a lack of LV function recovery.     

Off-pump obtuse marginal grafting with local stabilization: thoracotomy approach in reoperations.

BACKGROUND: Redo coronary surgery in patients with patent internal mammary artery (IMA) grafts may be hazardous. A thoracotomy approach has been used to graft the circumflex branches to avoid injury from sternal re-entry. Combining this approach with off-pump revascularization techniques may be useful. METHODS: Seven consecutive patients who had undergone prior coronary revascularization developed symptoms attributable to lateral wall ischemia. Five of them had patent IMA grafts. These patients underwent off-pump obtuse marginal grafting using local immobilization techniques via a thoracotomy approach. Inflow was from the descending aorta in 6 patients and splenic artery in 1. RESULTS: Obtuse marginal grafting was successfully performed in all cases without need for cardiopulmonary bypass. CONCLUSIONS: Off-pump obtuse marginal grafting via the thoracotomy route may be useful in redo coronary surgery, particularly in instances of patent IMA grafts.     

Skeletonization of gastroepiploic artery graft in off-pump coronary artery bypass grafting: early clinical and angiographic assessment

BACKGROUND: Recently skeletonization has been recognized as an alternative to pedicle harvesting of the internal thoracic artery as a technique that increases the length and caliber size of the graft compared with pedicled internal thoracic artery grafts; however, this is not yet popular for harvesting the gastroepiploic artery (GEA). We report here our experience of skeletonized GEA grafting in off-pump coronary artery bypass grafting with early clinical and angiographic results. The purpose of this study was to evaluate skeletonization of GEA grafting in off-pump coronary artery bypass grafting with a large patient volume. METHODS: One hundred sixty-eight patients including 131 men and 37 women (mean age, 65 years; range, 45 to 87 years) underwent the skeletonized GEA grafting in off-pump coronary artery bypass grafting. These patients represent 41% (168 of 407 patients) of those who underwent off-pump coronary artery bypass grafting operations during the same period. We used the GEA graft of choice in patients with right coronary artery lesion. Skeletonization was performed in a unique manner we developed. RESULTS: There were no in-hospital deaths among the study patients. One patient had a perioperative myocardial infarction, which was considered a result of vasospasm of the GEA graft. None of the other patients had severe morbidity. The patency rate of the skeletonized GEA graft was 98.1% (151 of 154 distal anastomoses). CONCLUSIONS: This study suggests that skeletonization of the GEA graft can enlarge its caliber size and improve its flow capacity. In addition, the acceptable early clinical and angiographic outcome suggests that use of the skeletonized GEA graft in off-pump coronary artery bypass grafting surgery is safe and effective.     

Aortocoronary shunting during off-pump coronary artery bypass surgery as acute reperfusion strategy in ST-elevation myocardial infarction

We report the case of a 43-year-old patient with acute ST-segment elevation anterior myocardial infarction who underwent off-pump coronary artery bypass grafting. To reduce the duration of ongoing myocardial ischemia, acute reperfusion of the infarcted coronary artery was achieved using an aortocoronary shunt, thereby perfusing the occluded left anterior descending artery. Under the protection of the aortocoronary shunt, the left internal thoracic artery was harvested and was thereafter anastomosed to the left anterior descending artery. The patient had an uneventful postoperative recovery.     

Perfusion-assisted direct coronary artery bypass: selective graft perfusion in off-pump cases

BACKGROUND: Hemodynamic instability during multivessel off-pump coronary artery bypass grafting can lead to hypotension, progressive myocardial ischemia, further hypotension, and the need for urgent cardiopulmonary bypass. METHODS: In 10 patients undergoing off-pump coronary artery bypass grafting, a novel technique of pressure-controlled blood delivery has been used that allows the immediate restoration of arterial blood to distal coronary beds after distal coronary anastomosis. This technique utilizes a servo-controlled pump to allow delivery of blood at systemic or suprasystemic pressures, and provides the option for infusion of supplemental additives for myocardial resuscitation, myocardial vasodilation, and enhancement of myocardial performance. RESULTS: Myocardial perfusion was successfully enhanced via one or two grafts in all 10 patients with an average graft flow of 98+/-8 mL/min. In 3 patients, a 27% increase in perfusion pressure led to a 59% increase in perfusate flow. All patients were hemodynamically stable after initiation of selective graft perfusion. CONCLUSIONS: Based on this preliminary patient series, the selective perfusion of grafted vessels seems to facilitate multivessel off-pump coronary artery bypass grafting by promoting rapid recovery of grafted segments, by enhanced hemodynamic stability during subsequent anastomoses, and by providing increased flexibility in the sequence of grafting.     

Changing pattern in beating heart operations: use of skeletonized internal thoracic artery

BACKGROUND: The use of skeletonized internal thoracic artery (ITA) was reported to be technically and hemodynamically beneficial in conventional coronary artery bypass grafting with cardiopulmonary bypass assistance. The purpose of this study is to evaluate the impact of changing from conventional to skeletonized ITA harvesting on early off-pump coronary artery bypass grafting outcome. METHODS: Between 1996 and 2001, 640 patients underwent systematic off-pump coronary artery bypass grafting (single surgeon experience). The ITA was pedicled (P) in the first consecutive 440 patients and skeletonized (S) in the subsequent 200 consecutive patients. Mean age, preoperative risk factors, sex, number of involved territories, and incidence of reoperations were similar in both groups. RESULTS: In group S, number of ITAs per patient (1.7 +/- 0.08 versus 1.2 +/- 0.05; p < 0.001), bilateral ITA (46% versus 27%; p < 0.001), ITA sequential grafts (27% versus 1%; p < 0.001), and T grafts (16% versus 3%; p < 0.001) were higher. Deep sternal infections were comparable in both groups (group S: 1%, group P: 1.2%; p = 0.38). Perioperative myocardial infarction, maximal creatinine kinase-MB level, and requirement for more than 24 hours of inotropic support were comparable in both groups. Thirty-day mortality was also similar (S: 1.7%, P: 1.6%). CONCLUSIONS: Changing to routine use of skeletonized ITA in off-pump coronary artery bypass grafting is a safe alternative to routine pedicled ITA. In our experience, this procedure has facilitated the use of ITA anastomosis without increasing sternal wound complications.